The chief executive of Canada's flagship airline, Air Canada, apologized Thursday for his lack of French proficiency after the revelation landed him in hot water in Quebec -- a staunch defender of the language of Moliere.

Michael Rousseau pledged he would work on improving his French as he apologized for causing offense by giving a speech almost entirely in English the day before in Montreal, where the airline is headquartered and where he has lived for many years.

"I want to make it clear that in no way did I mean to show disrespect for Quebecers and Francophones across the country," Rousseau said in a statement.

"I apologize to those who were offended by my remarks," he said, adding that Air Canada is committed "to show respect for French."

"As a leader, I will set the tone," Rousseau said.

Air Canada's CEO is in hot water over his apparent lack of proficiency in French
Air Canada's CEO is in hot water over his apparent lack of proficiency in French AFP / Daniel SLIM

After his speech to business groups on Wednesday and comments afterwards to journalists that he'd managed to get by without French for years, Rousseau faced a backlash from politicians -- including Quebec Premier Francois Legault and federal Languages Minister Ginette Petitpas Taylor -- as well as French language associations.

Canada has two official languages -- French and English -- and Ottawa requires most companies, notably airlines, to offer services in both.

Quebec is the only province where the official language is French, and it has over the years worked hard to fortify it, including introducing in May an update to a 1977 law reaffirming French as Quebec's main language and promoting its use locally on signage, in education and in workplaces.

According to Statistics Canada, French use in Quebec is in decline, with 71.2 percent of Quebecers saying in a recent survey that they speak French with their family and friends, down from 72.8 percent five years ago.